Method of treating sulfid ores.



, UNITED STATES PATENT OFFICE.

FRANK K. CAMERON AND J OHN A. CULLEN, 0F SALT LAKE CITY, UTAH, AND REEDW.

HYDE, OF NEW YORK, N. Y., ASSIGNORS TO AMERICAN SMELTING & BEFINING GOM-PANY, OF SALT LAKE CITY, UTAH, A CORPORATION OF NEW JERSEY.

MET OD or 'rnEA'rme SULFID onus.

No Drawing.

T.) all whom it may concern:

Be it known that we, (1) FRANK K. CAMERON, (2) JOHN A. CULLEN, and (3)REED W. HYDE, citizens of the United States, residing at (1) Salt LakeCity, (2 Salt Lake City, and (3) New York city, in the counties of (1)Salt Lake, (2) Salt Lake, and (3) New York, and States of (1) Utah, (2)Utah, and (3) New York, have invented certain new and usefulImprovements in Methods of Treating Sulfid Ores, of which the followingis a specification.

This invention is a method of treatlng sulfid ores for the recoverytherefrom of the metal values and elemental sulfur. method will'bedescribed in its application to complex sulfids carrying one or moresulfids of zinc, lead, co per and iron, together with some silver, go dand manganese, with other componentsand gangue minerals.

,We have discovered that "in presence of strong sulfuric acid and athigh temperatures, these sulfid ores undergo decomposi- I t-ion,yielding elemental'sulfur which distils from the mass, and the sulfatesof the metals which remain as a residue. probablytakes place in stages,and is not achieved or realized in practice .n a complete form; but itmay be summarized in the following ideal equation which ismore or. lessimperfectly approxlmated, namely 3 sof+4 s+uno A more or less closeapproximation tof his reaction is obtained W en tl.e ore, mixed withsulfuric acid having a concentration of Baum or higher, is raisedquickly to a temperature of about 200 0.. more or less. The sulfid oremay be simply mixed with the sulfuric'acid in about the proportionsabove described and the mixture quickly heated to the requiredtemperature. We prefer however, in order to secure more nearlv uniformtemperature conditions and a better approximation to the ideal reaction,to heat the sulfuric acid first nearly to its boiling point, and then toadd the ore.

. The reaction is' carried out in a still or ves- Specification ofLetters Patent.

The.

The reaction cific manipulation.

Patented Apr. 2, 1918.

Application filed June 18, 1917. Serial No. 175,529. I

lution of sulfur dioxid, and presently if the temperature besufficiently maintained by a copious evolution of elemental sulfur,mixed with water-vapor, sulfur dioxid and sulfur trioxid, or with vaporsof sulfuric acid. The sulfur is easil condensed and recovered and may bemar eted as such, while the to cool somewhat and 1s lixiviated withwater. We obtain thereby an aqueous solution containing practically 'allof the zinc, together with more or less ferrous iron, copper, aluminum,silver, etc. By well known and commonly practised methods all basesother than zinc are readily removed, leaving a technically pure solutionwhich may be used for the production of zinc sulfate, or of the chloridor other salts of zinc, or which may be electrolyzed for the productionof the metal. The precipitated iron, silver, etc., from the zinc sulfatesolution may profitably be added to the extracted residue, consistingmainly of lead sulfate but containing also gold, silver, silica,manganese, etc., and the mi'xturesent to the lead smelter.

While we prefer to heat the acid to a high temperature before adding theore, our invention is not limited to this or other spe- The more quicklythe mixture is brought to the requisite temperature, the more closelythe reaction will approach the ideal equation as above expressed. Weconsider therefore that any method whereby such rapid heatin ma be.

accomplished is equivalent to that escrlbed herein. The application ofthe principle of Le Chatelier indicates that an increased yield ofsulfur may be expected by carrying proximating the boiling-point of theacid,

distilling off sulfur, and recovering the metal values from the residue.

2. The method of recovering elemental sulfur and metal values fromsulfid ores,

which consists in quickly heating sulfid. ore

and strong sulfuric acid to a reacting temperature approximating theboiling-point of the acid, distilling off sulfur, and recovering themetal values from the residue.

3. The method of recovering elemental sulfur and metal values fromsulficl Ores, which consists in heating sulfuric acid having aconcentration of at least 50 Baume approximately to its boiling-point,adding 10

